Boltless Metal Stair Step System for Indoor/Outdoor Staircase Installation

ABSTRACT

The invention is a boltless metal stair step system that provides a simple way to install an indoor/outdoor metal staircase. The result is a structurally sound, lightweight, fire retardant staircase that can ultimately be finished with various materials such as stone, brick, wood, etc. Ordinarily a staircase is constructed using wood, concrete, etc., and in most cases a skilled person is needed to repair or install a new staircase. This invention comes ready to assemble and no staircase building experience is necessary; and because of the unique interlocking or “snap in” connections and the minimal use of parts and screws, it eliminates the need for intricate measuring, cutting and special tools. Also, the specially designed “snap in” connections and the method of installing the steps makes the replacement of staircase parts simple and convenient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of my previously filed provisional application: application number 61-056,532 filed on May 28, 2008.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

Building or installing any type of staircase can be a long process that requires skilled workers and temporary blocked entryways or exits. Traditional staircases are built to include stringers, risers and treads, and over the years there have been many different systems devised for staircase building. Modular and prefabricated systems such as U.S. Pat. Nos. 960,412; 2,171,951; and 5,899,032, attempt to simplify the stair building process but still require a good amount of drilling, measuring, and cutting. While similar to U.S. Pat. No. 1,701,659 in step design, my invention does not require any bolts for attaching the steps to the stringer or to other steps and instead relies on an interlocking system built into each step and stringer. The steps and stringers are predrilled for optional reinforcement, but once the interlocking system is locked, the staircase can be used as is without reinforcement.

FIELD OF THE INVENTION

This invention relates to the field of construction and more specifically the construction of staircases.

BRIEF SUMMARY OF THE INVENTION

This invention relates to a boltless metal staircase step system that is easy to assemble and requires no technical skill for installation. With just 4 main components: stringers, a starter riser, steps, and hardware for reinforcement, this system does not require cutting or drilling, and requires minimal measuring and basic tools, i.e. a hammer and screwdriver.

The object of this invention is to provide any person, skilled in the area of stair building or not, the ability to build their own staircase as needed. Another object of the present invention is to provide a staircase that can be used immediately upon construction, eliminating the need for blocked entryways and temporary staircases that can be dangerous and inconvenient. Another object of the present invention is to allow any person to create a metal foundation which can be clad with a variety of materials such as brick, concrete, stone, and wood for a customized appearance. Another object of the present invention is to allow any person to create a durable, fire resistant, level staircase that will not have to be replaced as often as traditional wooden or masonry staircases.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING DRAWINGS

FIG. 1. is a view of the steel concrete pan step.

FIG. 1.A is a view of the L shaped lips on each step that are at a 90 degree angle to the riser edges.

FIG. 1.B depicts the upper metal fold unique to the steel concrete pan step.

FIG. 1.C depicts the riser edge found on both ends of the step.

FIG. 1.D depicts the square shaped lips on each step that are at a 90 degree angle to the riser edges.

FIG. 2. is a view of the step modified for wood cladding.

FIG. 2.C depicts the lower metal fold unique to the wood cladding step.

FIG. 3 is a view of the step modified for anti-slip function.

FIG. 3.C depicts the grate pattern on the tread that makes the step anti-slip.

FIG. 4 is a view of the assembled staircase.

FIG. 4.A depicts the points at which the staircase and stringer lips interlock or “snap in” to each other and are hammered down to lay flat against the riser. These points are present on both sides of each step.

FIG. 4.B depicts the stringers in the system.

FIG. 4.C depicts the starter riser in its intended position.

FIG. 4.D depicts the points at which the staircase is attached to the floor and to a supporting structure.

FIG. 4.E depicts pre-drilled holes that can be used to reinforce the stringers to the steps.

FIG. 4.F depicts pre-drilled holes that can be used to reinforce the steps to one another.

FIG. 4.G depicts the square shaped lips on the stringers that abut the steps. These points are present on both sides of each step.

FIG. 5. is an exploded view of the staircase system showing how the entire system fits together.

FIG. 5.A depicts the stringers in the system.

FIG. 5.B depicts the L shaped and square shaped lips present on each stringer.

FIGS. 5.1, 2, and 3 depicts the order in which the steps are placed, beginning with the starter riser.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a boltless metal stair step system for indoor/outdoor staircase installation. The invention is comprised of the following:

-   -   (1) Step—Each steel concrete pan step (FIG. 1) is constructed to         have 4 L shaped lips: 2 on each side of the riser area along the         outer edges (FIG. 1.A). There is also one square shaped lip         (FIG. 1.D) on each side of the riser area along the outer edges.         The L shaped lips, which face downward, and the square shaped         lips are at a 90 degree angle from the riser edge (FIG. 1.C)         which will allow them to lay flat against the stringer once         connected. The front portion of the step has an upward metal         fold (FIG. 1.B) that will facilitate masonry cladding.         Alternatively, the front portion of the step can have a downward         fold (FIG. 2.C) that will allow it to be covered with wood or         the step can have a longer riser and several grates along the         top of the step (FIG. 3.C) to provide an anti-slip step. The         entire step has pre-drilled holes to facilitate final         reinforcement (FIGS. 4.E and 4.F).     -   (2) Starter riser—First steel riser to be placed at the bottom         of the staircase before the steps are placed (FIG. 4.C).     -   (3) Stringers—Each steel stringer is constructed to have 2 L         shaped lips and one square shaped lip (FIG. 5.B) per step in the         riser areas along the side edges. The L shaped lips, which face         upwards, and the small square lip will ultimately be hammered         down to lay flat against the riser of the step once connected.         Each stringer has a connection piece at the bottom for attaching         it to the floor and at the top (FIG. 4.D) for attaching it to a         supporting structure.     -   (4) Reinforcement hardware: self drilling tapping screws or pop         up rivets and anchor or machine bolts for attaching stringers.

The two stringers (FIG. 4.B) are positioned so that they are parallel to each other with enough space in between them to accommodate the steps that will be attached later. The starter riser (FIG. 4.C) is attached at the bottom to connect and space the stringers. The stringers are then affixed to the ground and to a supporting structure (i.e. a platform, porch, building, etc) at FIG. 4.D by using anchor bolts, screws, machine bolts or by welding. The steps are then placed one at a time, over and between the stringers from the bottom up The L shaped lips present on the riser area of both the stringers and the individual step lock into place firmly (FIG. 4.A). The steps can then be reinforced to each other with screws or rivets from the top of the staircase (FIG. 4.F) and the resulting staircase can be reinforced to the stringers by hammering the lips on the stringer (FIGS. 4.A & 4.G) down to lay flat against the riser of the steps and by using self drilling tapping screws or pop rivets at the sides (FIG. 4.E). The staircase can also be clad with wood, stone, brick and various other materials depending on the step used (FIGS. 2 & 3).

The front metal fold of the step can be constructed with a downward fold so that instead of masonry cladding, the steps can be covered with wood (FIG. 2). In addition, the step can be constructed with a longer riser and several grates along the surface of the step to provide an anti slip step (FIG. 3).

The invention can be used to build a temporary staircase, a permanent staircase or to remodel an existing staircase and the components of the invention can be galvanized or chemically coated for protection from the elements in outdoor environments.

The invention provides a simple method of building a metal staircase and with minimal measuring and no cutting or other material preparation, it can be assembled within minutes by any person, skilled or not. It also provides an immediate staircase, eliminating the need for improvised temporary staircases or ladders. The unique interlocking or “snap in” connections that connect the steps to the stringers are a significant improvement over other modular stairs that require intricate attachment of each step using screws. This invention can also be disassembled, meaning it can be moved from one location to another with minimal damage or it can be used as a temporary staircase. 

1. A boltless metal stair step system for indoor/outdoor staircase installation in which the stringers are secured to the floor and to the supporting structure (i.e. a building, a platform, etc) and the steps are placed one at a time, over and between the stringers from the bottom up beginning with the starter riser; the specially constructed steps are designed to interlock or “snap” into place at specific areas along the stringers, resulting in a staircase that can then be reinforced with self drilling tapping screws or pop rivets and covered with various materials.
 2. The boltless metal stair step system of claim 1, comprising: two stringers; a starter riser; steps; and reinforcement hardware.
 3. The boltless metal stair step system of claim 1, wherein said stringers can be secured to the floor and supporting structure using anchor bolts, screws, machine bolts or by welding.
 4. The boltless metal stair step system of claim 1, wherein said starter riser is placed at the bottom of the staircase and said steps are then placed consecutively over and between the stringers.
 5. The boltless metal stair step system of claim 1, wherein said steps are designed to interlock or “snap” into place at specific areas along the stringers.
 6. The boltless metal stair step system of claim 5, wherein the interlocking lips on the steps and stringers can be hammered down on each side for permanent staircase installation.
 7. The boltless metal stair step system of claim 5, wherein the interlocking lips on the steps and stringers can be left open for temporary staircase installation and subsequent disassembly.
 8. The boltless metal stair step system of claim 2, wherein said steps can be constructed to accommodate cladding with masonry or wood, or to have anti-slip step properties, by varying the fold, width and tread of the step.
 9. The boltless metal stair step system of claim 8, wherein said steps are designed to interlock or “snap” into place at specific areas along the stringers regardless of fold, width, and stair tread design.
 10. The boltless metal stair step system of claim 2, wherein said steps include predrilled holes for reinforcement and cladding.
 11. The boltless metal stair step system of claim 2, wherein said reinforcement hardware (self drilling tapping screws or pop rivets recommended) can be used to reinforce the resulting staircase.
 12. The boltless metal stair step system of claim 1, wherein the reinforced staircase can then be covered with various materials for custom cladding.
 13. The boltless metal stair step system of claim 1, wherein the system can be placed over an existing staircase of similar dimensions for the purpose of remodeling the staircase.
 14. The boltless metal stair step system of claim 2, wherein the mentioned components are constructed from steel for fire resistance and increased strength.
 15. The boltless metal stair step system of claim 2, wherein the mentioned components can be galvanized or chemically coated for weather resistance. 